Milwaukee Mayor Tom Barrett — Wisconsin Gov. Scott Walker’s 2010 opponent — announced Friday he is entering the race to challenge the Republican governor in the June recall.

Barrett is aiming for a rematch of his 2010 battle with Walker, which the Republican won 52 percent to 47 percent.

“We need to bring our state back,” Barrett wrote in an email to supporters. “Wisconsin needs a governor who is focused on jobs, not ideology; a leader committed to bringing our state together and healing political wounds, not pitting people against each other and catering to the special interests. This is the governor I will be for the people of Wisconsin.”

On Friday, Wisconsin elections officials ordered Walker’s recall, finding that there were 900,939 valid signatures submitted to trigger the election. The board voted unanimously for the historic recall, with the primary on May 8 and the general election set for June 5.

Barrett, 58, will vie for the Democratic nomination against three other declared candidates: secretary of state Doug La Follette, state Sen. Kathleen Vinehout and former Dane County executive Kathleen Falk. Falk and Barrett have also faced off in a previous Democratic gubernatorial primary in 2002. Both Falk and Barrett ended up losing in the primary to Jim Doyle, who won the general election and served as Wisconsin’s governor from 2003-2011.

“This was not a decision I made lightly,” Barrett wrote. “I love this state and I care deeply about our future. That’s why I ran for governor in 2010 - even though I knew it was an uphill battle.”

Walker’s campaign spokeswoman Ciara Matthews said it was “shocking” the governor’s former rival would run again, noting that “Barrett’s record of failed leadership as mayor of Milwaukee has twice been rejected by Wisconsin voters.”

“It is shocking that despite the downward spiral of Milwaukee’s economy that Tom Barrett has presided over that he would ask Wisconsinites to not only stop the progress the state has seen in Governor Walker’s first year in office, but completely reverse it by electing him as governor,” Matthews said in a statement.

In a Marquette Law School poll earlier this week, Walker holds a slight edge over Barrett with 47 percent to 45 percent. In the Democratic primary, Barrett tops all the possible candidates with 36 percent. Falk, who has raked in a number of top union endorsements, holds 29 percent of potential voters. Both Vinehout and La Follette have eight percent, and 17 percent told pollsters they are undecided.

Barrett told supporters he will “fight to restore collective bargaining rights, because it’s the right thing to do, and it’s necessary to heal Wisconsin.”

”Gov. Walker gutted education, cut women’s health, and diverted millions of dollars intended for Wisconsin victims of Wall Street foreclosure fraud to patch a hole in his budget,” Barrett wrote. “In response to this unanticipated assault on Wisconsin values, the people united and fought back.”

And “starting tomorrow, I will crisscross the state, taking our message directly to the people in every corner and working everyday to restore our values and move Wisconsin forward. With you standing with me, I know we will prevail,” Barrett wrote.

Falk said she welcomed Barrett’s entry in the Democratic primary.

“I welcome Tom to this important race. I have been working side by side with citizens around our state for over a year fighting hard against Gov. Walker’s extreme agenda,” Falk said in a statement. “I have a plan to reverse the damage that Gov. Walker has done – by bringing back openness, transparency, and accountability to government.”